Abstract
We previously reported that low-dose irradiation activated antioxidant function and inhibited brain edema induced by cold injury in mouse. In the present study, we pathologically examined the development of tissue damage in the cerebral hemisphere after cold injury by prior low-dose X-irradiation. Mice were irradiated by sham or 0.5 Gy of X-ray. At 4 hr after irradiation, the right cerebral hemisphere was injured by placing a cooled metal probe on the skull surface. Brains were removed at 0 (control), 1, 4, 24, or 48 hr after the cold injury. Cells became atrophied after cold injury. The number of cells in lesion area of sham irradiated group significantly decreased at 4, 24, or 48 hr. Those of 0.5Gy irradiated group were significantly decreased at 24 or 48 hr. Non-structural areas in lesion tissue of sham and 0.5Gy irradiated groups were significantly increased at 4, 24, or 48 hr. At 4 hr, those of 0.5Gy irradiated group were lower than those of sham irradiated group. It was significantly decreased the number of neuron in lesion tissue after sham and 0.5 Gy irradiation. At 1 hr, the number of apoptotic cells of 0.5 Gy irradiated group were significantly lower than that of sham irradiated group. These findings suggested that low-dose irradiation alleviated tissue damage induced by cold injury. These results supported to the previous report on the inhibition of brain edema induced by cold injury using biochemical assay.
